Pre-stack HTI Velocity Variation with Azimuth (VVAZ) and Amplitude Variation with Azimuth (AVAZ) are employed to locate open fracture networks at the Wolfcamp by detecting changes in azimuthal moveout and amplitudes caused by long, narrow bands of fractures associated with seismically mapped shallow graben features (Cook, McKee and Bjorlie 2019). Vertical fracturing within the Wolfcamp located beneath graben features mapped at the Lamar limestone horizon have demonstrated a fracture stimulation connection to excessive extraneous water and H2S in Wolfcamp horizontal wells within the Reeves County portion of the Delaware Basin. The working model assumes the shallow grabens are the result of middle-late Tertiary tectonic extension with faulting terminating at various depths: often directly beneath the Lamar limestone, but sometimes into the Bone Spring and even the Wolfcamp.
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